JP3170971U - Turbomachine rotor - Google Patents

Abstract

The turbomachine has an axially fixed transmission gear with axially directed gear face rotationally coupled to shaft (1). A collar (10) has axially directed collar face (17,17') that is spaced from the gear face by a clearance equal to more than the predetermined axial displacement with fixed axially on the shaft. The gear face and collar face are engaged each other so as to limit axial movement of the shaft on failure of one of the bearings (6,6') and axial overtravel of the shaft.

Description

  The present invention relates to a rotor of a turbomachine, particularly an integral gear turbomachine, in which a shaft and at least one impeller are components of the rotor, and the rotor is guided by a thrust bearing.

  The rotor of an integral gear turbomachine usually consists essentially of a helical gear pinion shaft and an impeller. In that case, the impeller can be installed only at the end of the shaft, or both shaft ends can be equipped with the impeller. Depending on the intended use of the turbomachine, a turbo compressor or an expansion turbine impeller is used.

  The rotor of the turbo compressor is driven through an integral helical gear, while the rotor of the expansion turbine is connected to a slow-moving large gear shaft via an integral helical gear or a common Drives the rotor of another turbo compressor placed around the large gear. The gear gears that mesh with each other are arranged so that the meshing is oblique with respect to the rotation shaft of the gears, and an axial force is generated during torque transmission. This axial force must be supported to ensure gear meshing. Usually, the axial force is supported by the housing via a thrust bearing via a shaft to which a gear and an impeller are fixed. Bearings that guide the rotor in the axial direction of the pinion shaft have some play.

  If a too strong axial motion stimulus acts on the thrust bearing, the play will be exceeded and the axial guidance will not function. This leads to severe damage to the turbomachine. Damage can occur as the impeller touches the opposing partial surfaces of adjacent housings with its blade arrangement narrowly spaced. In that case, it is in direct contact between the impeller and the housing or indirectly through the sealing element of the impeller. In particular, in a turbomachine that compresses or expands pure oxygen, contact with the casing of the impeller has a fatal result. Causes of frictional heat or sparks can cause catastrophic mechanical fires.

  In order to avoid such damage, the axial movement is usually grasped by measurement techniques during the operation of the rotor. When a certain boundary value is exceeded, appropriate safety measures are taken. This may be an operation alarm or a shut-off of the rotor drive. Both measures may be used simultaneously.

  After the drive is shut off, the turbomachine is gradually stopped. This gradual stop may take a long period of time before the rotor reaches a stationary state. This is due to the fact that the operating speed of turbomachines is usually very high and the high mass moment of inertia. The entire machine train (Machinenstrang) contributes to a high mass moment of inertia.

  Based on the rotor mass once accelerated in the axial direction, the axial motion stimulus continues to act during the period of gradual stopping. This can result in further axial movements during the gradual stop, resulting in a situation where the turbomachine is damaged even after a safe stop.

  The problem of the present invention is to avoid unacceptable axial movement which can lead to turbomachine damage in the event of overloading of the thrust bearing.

  In accordance with the invention, the object is that the rotor comprises at least one pressing collar as an additional axial guide element, in which the play between the pressing collar surface and the gear stopper surface is a thrust bearing. It is solved by being bigger than play. In normal operation, the thrust bearing is responsible for guiding the rotor. When an overload of the thrust bearing occurs based on the use of the bearing play, the pressing collar takes over the necessary axial guidance.

  The pressing collar portion is a disk-shaped bearing element, and is disposed on the front surface of the meshing gear by being integrally formed with the gear or by being fixed by an appropriate method as an independent member. In this case, the disk of the pressing collar portion fixed to the pinion shaft radially overlaps the opposing surface of the gear, and both of them move so as to slide.

  In accordance with the invention, two independent axial guidance systems are used in this way, i.e. a thrust bearing and a pressing collar in parallel. Since the play of the pressing collar is larger than the play of the thrust bearing, the axial guiding function is given to the surface of the pressing collar only when a predetermined axial movement amount is exceeded. Both axial guidance systems are positioned on the common pinion shaft of the rotor. These are coordinated with each other, and in normal operation the thrust bearing guides the rotor, while in the normal operation the pressed collar is operated with still acceptable play on the contact surface to the large gear.

  In a particularly advantageous embodiment of the invention, in addition, the axial movement of the rotor is captured by the measurement technique. If the boundary value is exceeded, the rotor drive is shut off. Thus, according to the invention, the use of two independent axial guidance systems and the measurement technical grasp of axial movement are combined with each other.

  Axial movement can be measured via a proximity probe. If the boundary value is exceeded, the rotor drive is shut off.

  It is also possible to monitor the axial movement of the rotor indirectly by measuring the temperature in the thrust bearing. In the carrier element that is loaded by the axial thrust, the temperature rises in the section receiving the load. The axial movement of the rotor causes a temperature rise in the thrust bearing. This temperature rise is grasped by the temperature sensor. When the boundary temperature is exceeded, the turbomachine drive is shut off.

  After shutting down the drive, the rotor gradually stops and finally stops after a long period of time. Since further axial movement may occur during this gradually stopping phase, the pressing collar takes over the axial guiding function according to the present invention. This avoids a situation in which the turbomachine is damaged in the phase of gradually stopping.

  The pressing collar is not subjected to a load during normal operation. This pressing collar is only used in the event of an error. Thereby, a press collar part can still exhibit a complete function at the time of the first use. The axially pressed collar surface is not required until an operational error occurs and can therefore still be fully loaded. In addition to this, the load on the pressing collar portion when gradually stopping decreases as the rotational speed decreases.

  During operating errors, the axial guidance of the rotor is taken over by two pressing collars or by only one pressing collar. When two pressing collars are used, each of these pressing collars comprises a pressing collar surface. Depending on which direction the axial movement of the rotor is carried out, one pressing collar surface of the pressing collar or the pressing collar surface of the other pressing collar corresponds to the gear. Takes over the guidance function by moving toward the stopper surface.

  As an alternative, it is also possible to use only a single pressing collar where both pressing collar surfaces are present. Therefore, in the event of an error, depending on the direction of axial movement, one surface of the pressing collar or the other surface takes over the axial guidance.

  It has been found that it is particularly advantageous if a stopper face is formed by the side wall of the keyway, when only one pressing collar is used, in the event of an error, the stopper face on which the pressing collar face proceeds. Preferably, the keyway is arranged around the gear of the helical gear.

  Both the thrust bearing and the pressing collar are preferably positioned on a common pinion shaft of the turbomachine helical gear. The pressing collar can be fixed to the shaft in various ways. It can be formed integrally with the shaft or can be fixed to the shaft as an independent member.

  Preferably, the play between the pressing collar surface and the stopper surface is smaller than the operating gap between the open impeller blade arrangement and the turbomachine housing wall. If the thrust bearing fails, it is avoided that the impeller comes into contact with the housing based on these different dimensions.

  If both impellers are open, there is an operating gap for each of these impellers. In this case, the play of both pressing collars needs to be smaller than these operating gaps.

  It has proven to be advantageous if the play between the pressing collar surface and the stopper face is smaller than the seal play between the impeller maze and the maze counter ring of the impeller with the cover disk. Thereby, it is avoided that the impeller maze contacts the counter ring of the maze fixedly attached.

  If both impellers are equipped with cover disks, there is a seal play between the impeller maze and the fixedly attached maze counter ring in each impeller. In this case, the play of both pressing collars needs to be smaller than the seal play between the impeller maze and the fixedly mounted maze counter ring.

  The apparatus according to the present invention can be used for various types of turbomachines. Therefore, a single impeller can be attached to the rotor, and it is also possible for the impeller to exist at both ends of the pinion shaft. In this case, both a turbo compressor impeller and an expansion turbine impeller may be used. If the rotor is equipped with two impellers, two turbo compressor impellers or two expansion turbine impellers may be a problem each time. It is also conceivable that a turbo compressor wheel and an expansion turbine wheel are used simultaneously.

  It has been found to be particularly advantageous to use the rotor according to the invention in the compression or expansion of pure water oxygen or a gas mixture having a high oxygen ratio. When such elemental gas mixtures are compressed or expanded, the minimal spark formation or frictional heat generated when the impeller contacts the housing can already lead to a catastrophic mechanical fire.

  Further features and benefits of the present invention will become apparent from the drawings themselves and the description of the embodiments made on the basis of the drawings.

Illustration of a rotor with two pressing collars Illustration of a rotor with one pressing collar

  FIG. 1 shows a rotor 1 of a turbomachine having a pinion shaft 2 of a helical gear 3. The rotor 1 is provided with an open turbo compressor impeller 4 and an impeller 5 having a cover disk. Axial guidance is provided by thrust bearings 6, 6 '.

The axial movement a or a ′ of the rotor 1 is measured by the non-contact proximity probe 8. The axial movement results in a temperature rise in the thrust bearing 6 or 6 ', which is grasped by the temperature sensors 7, 7'. A too high axial thrust F _ax or F _ax ′ means that one of the thrust bearings 6 or 6 ′ is overloaded. When a certain boundary value is exceeded, this indicates that the thrust bearing play S _L or S _L ′ has been used up, but the drive device of the drive shaft 9 of the helical gear 3 is shut off. After the drive device is shut off, the rotor 1 gradually stops for a while still until it comes to rest.

If the axial thrust F _ax or F _ax ′ still present when the rotor 1 gradually stops leads to further axial movement, the rotor 1 is not allowed from a certain point according to the present invention. Prevent axial movement. This is done by the pressing collar 10 or 10 '. The pressing collar 10 or 10 ′ is manufactured as an independent member and is fixed to the pinion shaft 2. The pressing collar 10 or 10 ′ takes over the axial guiding function, and the associated pressing collar surface 17 or 17 ′ advances towards the corresponding stopper surface 11 or 11 ′ of the large gear 12 of the helical gear 3. .

In normal operation, the thrust bearing 6 or 6 'is responsible for axial guidance. Only when an error occurs, when the thrust bearing is overloaded, the pressing collar 10 or 10 'is given an axial guiding function. This is ensured by the fact that the axial play S _K or S _K ′ of the pressing collar is somewhat larger than the play S _L or S _L ′ of the thrust bearing.

The contact of the impeller with the housing wall is caused by the fact that the axial play S _K or S _K ′ of the pressing collar is between the blade arrangement 13 of the open turbo compressor impeller 4 and the fixed housing wall 4. It is avoided by much less than the operating time gap S _G.

Similarly, the play S _K ′ of the pressing collar is clearly smaller than the seal play S _D between the turbo compressor impeller 5 with the cover disk and the maze counter ring 16 fixedly mounted.

Since the axial play S _K or S _K ′ of the pressing collar is greater than the thrust bearing play S _L or S _L ′, both pressing collar surfaces 17 or 17 ′ are fully loaded during normal operation. It moves without receiving. When the rotor 1 is gradually stopped, the pressing collar portion causes the axial movement of the rotor 1 that is not recognized, thereby causing the blade arrangement 13 of the impeller to contact the housing wall 14 or the impeller maze. It can be avoided that 15 contacts the counter ring 16 of the maze that is fixedly attached.

In FIG. 2, when one of the thrust bearings 6 or 6 'fails, the only pressing collar 18 takes over the axial guidance. The pressing collar 18 has both pressing collar surfaces 17 or 17 ′. The pressing collar 18 rotates within the keyway 19 of the large gear 12. The key groove 19 is arranged around the large gear 12. The keyway 19 is opened radially outward. The stopper surface 11 or 11 ′ is formed by the side wall of the key groove 19. There is a play S _K or S _K 'between the pressing collar surface 17 or 17' and the stopper surface 11 or 11 '. When the thrust bearing is overloaded, the pressing collar 18 takes over the guiding function in the failure operation. In doing so, each pressing collar surface 17 or 17 'moves relative to the corresponding stopper surface 11 or 11'.

DESCRIPTION OF SYMBOLS 1 Rotor 2 Pinion shaft 3 Helical gear 4 Impeller 5 of turbo compressor 5 Impeller 6 and 6 'with a cover disk Thrust bearing 7, 7' Temperature sensor 8 Proximity probe 9 Drive shaft 10 Pressing collar part 11, 11 'Stop surface 12 large gear 13 blade arrangement 14 housing wall 15 impeller labyrinth 16 labyrinth counter ring 17, 17 ′ pressing collar surface 18 pressing collar 19 keyway

Claims (9)

The rotor (1) of the turbomachine, in which the shaft (2) and at least one impeller (4, 5) are components of the rotor (1) and the rotor (1) is guided by the thrust bearing (6, 6 ′) In 1)
The rotor (1) comprises at least one pressing collar (10, 10 ') as an additional axial guide element, in which case the pressing collar surfaces (17, 17') and the gear (12) Rotor (1) characterized in that the play (S _K , S _K ′) between the stopper surfaces (11, 11 ′) is larger than the play (S _L , S _L ′) of the thrust bearing (6, 6 ′). ).   The rotor drive device is shut off when the axial movement (a, a ') of the rotor (1) is ascertained by a measurement technique and exceeds a boundary value. rotor.   When the thrust bearing (6, 6 ′) stops functioning, the corresponding pressing collar surface (17, 17 ′) is directed toward the stopper surface (11, 11 ′) of the corresponding gear (12). The rotor according to claim 1.   Rotor according to claim 1, characterized in that both axial guiding elements (6, 6 '; 10, 10') are positioned on a common shaft (2) of the rotor (1). The play (S _K ) between the pressing collar surface (17) and the stopper surface (11) is between the blade arrangement (13) of the opened impeller (4) and the housing wall (14) of the turbomachine. The rotor according to claim 1, wherein the rotor is smaller than the operating gap (S _G ). Play between the pressing flange-shaped portion plane (17 ') and the stopper surface (11') _{(S K} ') is, wheel maze (15) and labyrinth counter ring wheel having a cover disc (5) (16 the rotor of claim 1, wherein the smaller the seal clearance (S _D) between).   The rotor (1) includes two pressing collars (10, 10 '), and each pressing collar (10, 10') has one pressing collar surface (17, 17 '). The rotor according to claim 1.   2. The rotor according to claim 1, characterized in that the rotor (1) comprises a single pressing collar (18), on which both pressing collar surfaces (17, 17 ′) are present. rotor. The rotor according to claim 8, characterized in that the stopper surface (11, 11 ') is formed by a side wall of the keyway (19), the keyway being arranged around the gear (12).

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